1. Field of the Invention
The present invention relates to a semiconductor device package and a method of manufacturing a semiconductor device using a semiconductor device package, and more specifically, to a semiconductor device package for packaging a semiconductor chip that processes a signal in a radio frequency band, and a method of manufacture a semiconductor device using such a semiconductor device package.
2. Description of Related Art
A semiconductor chip with a radio communication function is used for mobile communication equipment and RFID (Radio Frequency Identification). For radio communication with a mobile communication equipment or a reader/writer a radio signal in a 2.45 GHz frequency band is used. An antenna suitable for the used radio frequency band is connected to the semiconductor chip. The semiconductor chip typically has an RF (radio Frequency) input/output circuit connected electrically with the antenna, and a data processing section for processing digital signals. An input/output circuit for digital and analog signals may be contained. Such a semiconductor chip inevitably has a plurality of pad electrodes connected to an output terminal of the RF input/output circuit and an input/output terminal of the input/output circuit.
In order to protect the circuits mounted on the semiconductor chip from the destruction due to ESD (Electrostatic Discharge), an ESD protection circuit is generally built on the semiconductor chip.
FIGS. 1A and 1B are schematic circuit diagrams showing an ESD protection circuit 200. FIG. 1A is an example of a circuit diagram of the ESD protection circuit 200. A signal applied to a pad electrode 201 is supplied to an input buffer 204. The ESD protection circuit 200 is composed of a resistance 202, a diode 203 and a diode 205. A surge voltage applied to the pad electrode 201 due to the ESD is discharged to a power source line and a GND (Ground) line 206 by the diode 203 and the diode 205 via the resistance 202. The surge voltage applied to the pad electrode 201 is decreased due to the resistance 202, and also clamped by the diodes 203 and 205. This prevents the surge voltage of the electrode pad 201 from being applied directly to the input terminal of an input buffer 204 in the ESD protection circuit 200.
FIG. 1B is an equivalent circuit diagram related to the ESD protection circuit 200 of FIG. 1A during an AC operation. PN junctions of the diode 203 and the diode 205 act as a capacitance 213 and a capacitance 215 during the AC operation, respectively. As a result, the ESD protection circuit 200 behaves as a low-pass filter composed of the resistance 202 and the capacitances 213 and 215. As a result, when the pad electrode 201 is connected to the antenna, the property of the AC signal with the radio frequency band supplied from the antenna is considerably deteriorated due to the ESD protection circuit 200.
However, when the ESD protection circuit 200 is not connected to the pad electrode 201, the ESD destruction will occur at the time of handling the semiconductor chip and a semiconductor device, i.e., when the RF input/output circuit to which the ESD protection circuit 200 is not connected is electrically connected to an external terminal of the semiconductor device via a pad electrode. If the surge voltage due to the ESD is applied to the external terminal unprotected against the ESD destruction at the time of mounting such a semiconductor device on the mobile communication equipment, the RF input/output circuit will be destroyed, and thus the mobile communication equipment becomes defective. When being mounted on the mobile communication equipment without applying the surge voltage due to the ESD, the semiconductor chip resists the ESD destruction at the time of the handling thereafter.
U.S. Pat. No. 7,095,372 discloses an integrated circuit package in which an antenna is built. The integrated circuit package includes a semiconductor chip, and a multiple-folded conductor pattern serving as an antenna, both mounted on a board. The semiconductor chip and one end of the antenna are connected by bonding wires, and the other end of the antenna is terminated within the integrated circuit package without connecting to an external terminal of the integrated circuit package. That is, the conductor pattern serving as the antenna does not connect to the external terminal, and thus the semiconductor chip, which is connected to the conductor pattern by the bonding wire, does not connect to the external terminal.
When an antenna is built therein, a size of the semiconductor device becomes larger. It is certainly possible to fold the antenna complicatedly by use of a short coil and a top-loading technique. However, the use of these miniaturization techniques causes the degradation of the properties of the antenna such as narrowing of the frequency band and decrease of a gain. The communication possible distance generally has the highest priority, so that it would have to be said that a loss in an antenna portion is a fatal defect.